A conventional active magnetic regenerator is disclosed in U.S. Pat. No. 6,826,915. As shown in FIGS. 1 and 2, in accordance with the conventional active magnetic regenerator including the above-described cycle, a temperature of the heat transfer fluid heated in a first AMR bed 10A in the magnetic field is dropped to an atmospheric temperature by a hot-side heat exchanger 70 and the heat transfer fluid is then passed through the second AMR bed 10B. At the same time, since the second AMR bed 10B is outside the magnetic field, a magnetic refrigerant material layer 16 has a low temperature, the temperature of the heat transfer fluid drops while passing through the magnetic refrigerant material layer 16. The heat transfer fluid having the low temperature passes through a cold-side heat exchanger 60 and then enters the first AMR bed 10A to be heated. The heat transfer fluid then flows to the hot-side heat exchanger 70, the second AMR bed 10B and the cold-side heat exchanger 60 to complete the one cycle. Contrarily, when the second AMR bed 10B is moved to a magnet circuit 22 by a movable mechanism 24, a channel switch 30 reverses the flow of the heat transfer fluid to generate a reverse cycle.
On the other hand, as shown in FIG. 2, an AMR bed 10 includes a container 12 of a cylinder type, a plurality of magnetic refrigerant material layers 16 stored inside the container 12, and meshes 14. The container 12 includes heat transfer fluid inlet/outlet ports 18a and 18b, which may be connected to the heat exchange tube 32 or 34.
However, with respect to a direction of an arrow in FIG. 1, the inlet port 18a of each of the reciprocating AMR beds 10 is a near-side inlet port 18a close to the magnet circuit 22, and the outlet port 18b is a far-side inlet port 18b far from the magnet circuit 22. Therefore, a temperature of a magnetic refrigerant material 16a at the near-side inlet port 18a is higher than that of a magnetic refrigerant material 16b at the far-side inlet port 18b the near-side inlet port 18a enters the magnet circuit 22 first and the far-side inlet port 18b enters the magnet circuit 22 last.
The heat transfer fluid flows as shown in FIG. 3 when the AMR bed 10 is at the magnet circuit 22 since the near-side inlet port 18a of the first AMR bed 10A and the far-side inlet port 18b of the second AMR bed 10B having such a temperature distribution is thermally coupled to the cold-side heat exchanger 60.
That is, a temperature slope changes from a dotted line (prior to the flow of the heat transfer fluid) to a solid line (after the flow of the heat transfer fluid) since the heat transfer fluid having the atmospheric temperature that has passed through the cold-side heat exchanger 60 flows from the hot-side to the cold-side. Therefore, the conventional active magnetic regenerator cannot be used in accordance with an original purpose thereof such as in an air conditioner due to a performance degradation since an initial temperature is erased due to the heat transfer fluid flowing from the hot-side to the cold-side.